Add optional BMA456 accelerometer init on shared I2C bus.

Probe and configure the sensor when present; log and continue boot if
init fails so boards without BMA456 still run normally.

Co-authored-by: Cursor <cursoragent@cursor.com>

main/CMakeLists.txt

@@ -19,6 +19,7 @@ idf_component_register(
   "client_registry.c"
   "esp_now_comm.c"
   "esp_now_proto.c"
+  "bosch456.c"
   "proto/uart_messages.pb.c"
   "proto/esp_now_messages.pb.c"
   "proto/pb_encode.c"
@@ -36,7 +37,8 @@ idf_component_register(
   esp_driver_gpio
   esp_driver_uart
   esp_driver_i2c
-  app_update)
+  app_update
+  bma456)
 
 target_compile_definitions(${COMPONENT_LIB}
                            PRIVATE "POWERPOD_GIT_HASH=\"${POWERPOD_GIT_HASH}\"")